September 11, 2007—The mummy of an ancient Inca girl sits literally frozen in sleep at a museum in Argentina.

The mummy, called La Doncella or The Maiden, is that of a teenage girl who died more than 500 years ago in a ritual sacrifice in the Andes Mountains.

The girl and two other children were left on a mountaintop to succumb to the cold as offerings to the gods, according to the archaeologists who found the mummified remains in Argentina in 1999.

National Geographic Explorer-in-Residence Johan Reinhard, who co-led the expedition, described the discovery at the time as "the best preserved of any mummy I've seen." (National Geographic News is a division of the National Geographic Society.)

The High Country Archaeological Museum in Salta, Argentina, unveiled La Doncella, the oldest of the three victims, for its first public viewing on September 6.

The museum is displaying the mummy in a refrigerated, low-oxygen environment to reproduce the high-altitude conditions that allowed for its remarkable, natural preservation.

The mummies of the other two children remain in storage for further study, museum officials said.